WASHINGTON, D.C. -- As the gun control showdown approaches in the Senate, the family members of eight Sandy Hook victims came to Capitol Hill to lobby lawmakers Tuesday.

At a hearing in February Neil Heslin testified about Jesse, his first grade son, shot at Sandy Hook Elementary.

"Jesse was brutally murdered 20 minutes after I dropped him off," a tearful Heslin told members of Congress.

In a new ad the grieving father says that Jesse deserves tougher gun control.

Still, 14 GOP Senators threatened a filibuster to block a vote on gun control, even though a ban on the sale of assault weapons and high capacity magazines were stripped from the bill.

The Newtown visitors are outraged.

So are their senators.

"It is insulting to the families of Sandy Hook, Connecticut who have gone through this tragedy and not even get a vote on the floor of the Senate on a gun violence package that 90% of Americans support," noted Senator Chris Murphy.

A gun show compromise was in the works, allowing the buying of firearms face-to-face without background checks, but requiring checks for all other sales.

40% now happen without them.

Senate Majority Leader Reid demanded a decision, putting up a photo that named the Newtown victims.

Vice President Biden put the pressure on conservative lawmakers as well.

"People say 'What you're going to say to the NRA'. I got question for you. What are you going to say to the parents?" Biden asked.

The filibuster seems to be falling apart, with a vote on tough background checks possible later this week.

If that happens and the bill passes, most observers say the credit goes to the families from Newtown.